It's worth note that cryptocurrencies (and cryptography itself) have drifeted in and out of legality in many countries over the years so one should stipulate in which country one is talking about. I'm talking about the U.S. since I'm a citizen of that country
In fact it does not sound plausible. But even so law-abiding citizen, and if that happens then I will stick to the law.
It seemed eminently plausible to me but...it would be damn difficult to justify since the government themselves auctioned off coins from the Silk Road haul. It suprised and delighted me that they did so for this reason.
One of the driving forces behind my timings on taking a Bitcoin position back in 2011 was that I anticipated it becoming illegal to do so. I mis-estimated about this. I don't get everything right.
The positive treatment that Bitcoin received in the media and even in the judicial system (if one analyzed clearly) was a bit of a surprise to me and I forged a set of plausible explanations. One of these was that Bitcoin is in fact a marvelously honey-pot to attract various kinds of people and put them in uncomfortable positions. That has not (yet) happened to me, but I have been somewhat paranoid about it and have bent over backwards to keep my nose clean.